There are several classes of globular, lipid-containing particles, known as lipoproteins, that circulate in human blood and transport nonpolar lipids, primarily triglycerides and cholesteryl esters, through the plasma. Lipoproteins are classed according to the composition of the nonpolar lipids in the core of the particle and according to the composition of the apoproteins on the surface, and the density size and electrophoretic mobility of the lipoprotein (Harrison, 1991).
Recent studies have shown various disease associations with above-normal or sub-normal levels of certain lipoproteins. It is known, for example, that serum Lp(a) is elevated in subjects with gout (Takahashi, et al., 1995), various types of cancer, such as breast cancer (Kokoglu, et al., 1994), hyperthyroidism (Yamamoto, et al., 1995), and in Type 1 diabetics with early and established renal disease (Groop, et al., 1994). It has also been shown that there is a direct correlation between development of post-angioplasty restenosis and elevated serum Lp(a) concentrations (Tenda, et al., 1993).